Process of producing alkyl sulphates and alcohols therefrom



s. BORN ET AL FiledV may 1 1919 nPROCESS OF PRODUCING ALKYL SULPHATESAND ALCOHOLS THEREFROM l limatented dem.. 21, 193v i SHDNEY BORN, FBARTLESVILLE, AND ROBERT MELYNE ISI-IAM, 0F GKMULGEE,

G.'9.'KI.IAHO1M[.A,i ASSIGNORS, BY MESNE ASSIGNMENTS, T0 SETE IB. HUNT,TRUSTEE,

OF MOUNT' KISCO, NEW YORK PROCESS OF PRODUCING ALKYL SULPHATES ANDALCOHOLS TEREFROM Application filed May 1,

rllhis invention relates to a process of producing alcohols and mixturesofalcohols from oil gases.

to removethe higher olefines and the purified gas is treated to producethe alcohol. 4 When the object isto pro-duce the higher alcohols thegases are dissolved directly in sulphuric acid and the resultingmaterial treated to recover the alcohols. These processes have thedisadvantage that the higher4 olefines con tained in the gas arepolymerized byr this treatment with the result that the yield of alcoholismaterially reduced and that the polymerization products causedifficulties in the later steps of the process.

It is anobject of the present -inventlon to provide a lprocess in whicha high yield ofr alcohol is obtained from oil gases Withou'tpolymerization of the higher olefines.

It is a further object of the invention to provide a process in whichthe olefines are selectively absorbed to yield different alcohols fromthe complex mixtures of olefines,

obtained from oils.

Vith these and other objects in vlew the invention consists in the.process of making` alcohols hereinafter described and claimed.

In the accompanying drawings is shown a diagrammatic' illustration of anapparatus in vwhich the various steps of the process of making alcoholsfrom oil gases may be carriedon. Oil gases suitable forpse in theprocess may lower hydrocarbons. The cracking of petro-` leum or otherhydrocarbon oils may be carried on in a vacuum,1 at atmosphericpressureor l under greater than atmosphericpressure. It

has been found that the `gases evolved on cracking oils at low pressurescontain large amounts of ethylene and also considerable amounts ofhigher olefines, such as amylenes 'and' butylenes. The gases evolved oncracle ing petroleum under higher pressures contain 1919. Serial No.294,013.

large amounts of butylenes and amylenes with v smalladmixtures of otherolefines.

To obtain alcohols from oil gases in accordance with thepreferred formof the invention, the gases from a cracking retort are first compressedand cooled. A small amount of Water and some hydrocarbon vapors will becondensed at this point in the process and these are removed to beblended with gasoline. The cooled and compressedgases containing theolelines are then led into the first of a series of absorbing units.Here they 4come in contact with sulphuric acid cooled to a temperatureof about *25 C., which acid contains sulphuric acid esters of lower'alcohols formed by the absorption of oleines at a later stage in theprocess. In this unit the higher oleines, such as amylenes andbutylenes, are absorbed to form esters of the correspondin alcohols.From the first absorbing unitte gases pass to a second absorbing unit inwhich the lower olefines, such as propylene, are absorbed to form thecorresponding esters. vThe sulphuric acid in the second unit is at ahigher temperature and contains esters of still lower alcohols obtainedl4in a later absorption unit. From the second' absorbing unitthe gases,which now contain only the lowest members of the olenes, pass to thefinal absorbing unit where they come in contact with concentratedsulphuric acid maintained 'at a higher temperature than the temperatureof the second unit. Here the ethylene is absorbed to form ethylsulphuric acid. The sulphuric acid is passed from the.

Afinal to the first absorption unit counter to the current of gas. Theesters obtained in the above manner may then be hydrolyzed and distilledto obtain the corresponding alcohols.

In' the drawings lis illustrated a diagrammatic apparatus or flow sheetin which the preferred process of the invention may be carried out asfollows: v

Ol'gases from agasometer, or other' source l0, tiow to a compressor-12,where they are compressed to a pressureof Y.trom 50 to 200 pounds persquare inch.. The compressed'- gases then pass through a condenser 14where they are. o'oled to such a temperature that the major part of thewater and some hydrocaresV sor ed from the mixture of bon vapors arecondensed. These gases then pass into a separator 16, Where entrainediquid particles are separated therefrom. The liquid from the separator16. is then passed to a gasoline blending apparatus 18 and agitator 20,and from thence to storage.

The gases leaving the separator 16 pass to the first absorber 22 of anabsorbing unit 22, 24, 26 and 28. These absorbers 22-28 may be of anystandard type capable of being cooled to the desired temperature and ofbringing the olefines in the gases into intimate contact with anabsorbing acid solution. The gas enters the first absorber 22 of the'unit by a pipe 30 and passes from this absorber to the second absorber24 by a pipe 32. It then passes in a similar manner to the absorbers 26and 28 by means ci pipes 34 and 36. Bypass pipes 38, 40, 42 and 44 areprovided whereby any of the absorbers 22--28 may be cut out of the unit.In the piping arrangement, suitable Valves (indicated as crosses on thepipes) are provided to obtain the desired circulation of gas andliquids. The acid which is used to absorb the oleines passes from acooler 46 in a reverse direction to the direction of the flow of thegases through absorbers 28, 26, 24 and 22 by means of the respectivepipes 48, 50, 52 and 54, and leaves the unit thru a pipe 56. Each of theabsorbers 22-28 is maintained at a temperature of about 25o C., at whichtemperature the am lenes and butylenes are selectively abgases to formthe corresponding esters.

When a mixture of oleiines, such as exists in oil gases, is broughtdirectly into Contact with sulphuric acid at the usual atmospherictemperatures, the greater part of the higher olefines, the butylenes,amylenes and hexylenes, are polymerized and do not form the esters ofthe acid. This polymerization causes a decreased yield of higheralcohols, particularly of secondary and tertiary amyl and butylalcohols,'and also produces substances which interfere with theseparation of diolefins in the dilution tank. We have discovered thatwhen a very low temperature, that is a temperature of about 25 C. is

employed while carrying out the absorptiony By using these lowtemperatures, therefore,l

the higher oleines may be selectively absorbed and a much higher yieldof the higher alcohols may be obtained. With some oil gases the higherolefines may be effectively esterified at temperatures as high as 5O C.,

but with gas containing a higher percentage of higher olefines theAlower temperatures are preferred.

We have, morover, found that the polymerization ofthe higher oleines maybe reduced to a negligible amount if the sulphuric acidused containslower oleines which are present in the form ot the sulphuric esters oflower olefines. sorbing medium, sulphure acid which has been used as anabsorbent for the lower ole- 'ines in later steps of the process.However,

with certain types of gases, sulphuric acid which does not contain loweroleiines may be usedwithout forming a prohibitive amount ofpolymerization products. In this case fresh sulphuric arid mayY besupplied at the proper teinieratures to each stage ot' the absorbingoperation.

From the first absorbing unit the gases, now freed from the higheroleiines, pass thru a pipe 63 to absorber 64 of a second absorbing unit64, 66, 68 and 70, which has a construction and piping arrangementsimilar to the construction a-nd piping arrangement of the firstabsorbing unit. The gases pass consecutively thru absorbers 64, 66, 68and 70 in the same manner as in the first absorbing unit.

In the absorbers 64-70 the gases come in contact with sulphuric acidwhich is supplied from a lcooler 72 and Hows thru the absorberscounter-cmrent to the flow of gas. A temper ature of from ll()O to 200C. is maintained in these absorbers at which temperatures the propyleneis selectively absorbed from the gases passing thru thel unit. Thepropylene is more completely and readily absorbed Without polymerizationat these higher temperatures,

particularly when the amylenes and butylenes have been previouslyremoved. Ethylene, which is' not readily absorbed at this temperature,passes out of the unit with the gases leaving absorber 70.

From the second absorbing unit thev gases, which now contain practicallyno oleines except ethylene, pass through'the third absorbing unitconsisting of absorbers 76, 78, 80\and 82. These absorbers have aconstruction and piping arrangement similar to the construction. andpiping arrangement of thev absorbers of the first and second units.Concentrated sulphuric acid is introduced into the third absorbing unitthru a pipe 84 and flows thru the unit counter-current to the How ofgas. A temperature ofv approximately 90 C. is maintained in the thirdabsorbing unit, at which temperature the ethylene is readily absorbedwith the formation of ethel sulphurie acid. The 'unabsorbed gases thenpass from the apparatus thruV pipe 83, and

may be conducted to storage or to a furnace to be burned.

The course of the acid, in the absorption system, is as follows:Concentrated sulphuric acid, of 1.84 specific gravity, is taken from thestorage tank 86 by a pump 88 and forced through the pipe 84 to absorber82 of the final absorption unit. The acid thenviows, by gravity,successively through the units' 82,80, 78 and 76 and Therefore, We useas an aba Y a tank 122 yor rectiiied in a still 124. rlfhe vapors fromthe still 124v are condensed in meteor 94 iorces the acid through thecooler 46 and through the first absorption unit. Coolers 46 and 7 2 maytorni a part of the corresponding absorption units 22428 and 641-?? Q,or in case sucient cooling eiiect can be obtained in the absorbersthemselves these preliminary coolers 46' and 'l2' may be omittedentirely. Fllhe acid liquor flows from the absorber 22 ot the rstabsorption unit to the separator 58 Where the unabsorbed condensate isremoved. lThe acid liquor, which now has a specic gravityot about 0.95,passes to a dilutionv tank 96 and the unabsorbed condensate passes tolthe gasoline blending'y apparatus -62 and agitator 29..

p 1n the dilution tank 96, the acid liquor is diluted vvithapproximately three volumes oit vvater tor each volume, of acidoriginally supplied to the absorber whereupon any ole' vhues which mayhave been polymerized dury y' ing the process separate out and areremoved to a dioleiine tank'9'8. From the dilution tank the dilute acidliquors ilowlto still 100,

Where the mixtures ot theesters are hydrolzed and distilled.. Theheavier alcoholvapors from the stilldlOO- are collected in acondenserbox 106and drawn oid to a storage tank'108. The alcohol is then taken toa' rectitying still 110, Where the vapors are selectively separated and'condensed the condenser 112, and run'into storage tanks 114, 116 and 118(for amyl, butyl and prop'yl alcohols respectively). The ethyl alcoholis condensed in a condenser 120 and storedin a condenser 126 and the`finished product stored in a tank 128. rlhe dilute acid remaining alterdistillation in the still 100 is dravvn ed to a dilute acid storage tank130.

. 'llhis acid may loe-brought to the lead pans 132 and still 134 to beconcentrated and then returned to the tank 86 to re-enter. the process.

i .tanks 114, 116, 118 and 128.

When it is desired tolproduce separate solutions in the di'erentabsorbing units, acid trom the storage tank 86 is separately 'circulatedthrough each of the labsorption units.

. Ylhe acidto be used for absorbing the 'higher 4oletines, suchasamylene andv butylene in the rst absorbing unit is then taken.. directlytrom the storae tank 86, or other source, by the pump 94 t rough a pipe136 and forced directly through the cooler 46 and first absgrptionunit'22---28. The Iiquidleavingthe `under 4pressure by the `advantageabsorbing unit 22-28 then contains only esters of amylene and butyleneand is passed to the separatorS and dilution tank 96, as describedabove. This liquid is then separately treated in the stills 100 and 110to recover amyl and' butyl alcohols. nilhe acid to be used in the secondabsorption unit 64I-J70, for separately recovering the propylene, istaken by the pump 92 directly trom the storage tank 86' through a pipe138-and forced through the cooler 72 to the second absorption unit. Theacid containing'propyl esters is then removed trom the absorber 64 ofthe unit 64-70 through a `valve 140 andpipe 142. The acid solution isthen hydrolzed in the tank 144 and` then separately treated in stills100 and 110 to recover propyl alcohol. The acid tol be used in the thirdabsorption unit Z6-82,or separately recovering the ethylene is taken bythe pump 88 directly from the storage tank 86 through a pipe 84 andforced to the third absorptionV unit. rlhe acid containing the ethylesters is then removed from absorber Z 6 of the-unit Z6- 82 through `avalve 146 and pipe 148 to a dilution tank 150. The acid solution isthenhydrolyzed in the tank 150 and is then separatelytreated in stills100 and 110 to recover the ethyl alcohol. y

lllhe absorption ot the oletines in4 all Vof the absorption units iscarried out under pressure to assist in an edective select-iveabsorption and to provide a minimum polymerizationof the .olenes The oilgas is placed compressor 12 and the acid is' placed under pressure bythe pumps '88, 92. and 94. ln accordance with the gas being treated andthe type ot esters being formed, a pressure or from to 200 pounds persquare inch is maintained in the absorbing units.

llhe use of separate portions of sulphuric acid in each of the absorbingunits has the oit :forming separate solution of the esters, and may beused with some types of gases without substantial losses bypolymerization. y

YWith the above process the most complex mixtures of gases can betreated so as to selectively absorb ,the various oleines under thoseconditions which are most suitablelitor the absorption oit eachindividual oletine.. Moreover, the process can be so manipulated as toproduce a mixture of esters With a minimum of polymerization products.

The above detailed description of the proc- I in practice. llt isevident that modifications may be introduced in some of the steps oftheprocess, that' the types and numbers of absorbers may be varied tosuitndiierent types of gases and that the treatment of the productsobtained in different stepsmay be varied.

without departing from the fundamental features of the invention.

In making mixtures of alcohols the proper temperature conditions may insome cases be maintained in using less than three absorbing units and itmay t-hen beof advantage to use two units. While the process has beendescribed as carried out in stages in separate absorbing units as thismethod appears to permit of better temperature control, this may bevaried'by not dividing the absorbers in separate units and by passingthe gas and acid counter current to each other and gradually andcontinuously increasing the temperature in the direction in which thegas flows.

Having thus described the invention what is claimed as new is:

1. Those steps -in the lprocess of producing alcohols from oil gaseswhich comprise pass-- ing at one stage cooled and compressed gas into anabsorbing menstruum maintained at a lowk temperature, said menstruumvcontaining "sulphuric acidand acid derivatives obtamed by the absorptionoflower olefines in alater stage of the process, absorbing theunabsorbed olefines in a later stage in sulphuric acid counter-currentto the gases, and cooling it to the required temperature ateachabsorption stage.

2. Those steps in the process of producing alcohols from oil gases whichcomprise ab.

sorbing at one stage the higher olelines from the cooled gas underpressure in sulphuricacid at a temperature of about --25 C. andcontaining products formed from lower olelines absorbed at later stages,vabsorbing the higher members of the unabsorbed olefines at f a laterstage in sulphuric acid 'at a temperature of 10-20 C. and containingproducts formed from lower oleines, absorbing the un-` absorbed oleinesin concentrated sulphuric acid at a temperature of about 90 C. passingsulphuric acid from the last absorber .to the first absorbercounter-current to the flow of gases, and cooling to the requiredtemperature at each absorbing stage. y

3. Those steps in the 'process of producing alcohols from oil gaseswhich comprise selectively absorbing the heaviest olenes from oil asesin sulphuric acid at a temperature of a out 25 C., absorbing .lightermembers of the unabsorbed oleines in sulphuric acid at 10-20 C., andabsorbin light olefines in concentrata? at 90 C. y

4. The process of making alcohols from oil sulphuric acid gases which'comprises selectively absorbing the heaviest olefines from oil gases insul- -phuric acid at a temperature of about -25 C., absorbing lightermembers of the unabsorbed olefines in sulphuric ,acid at 10-20 C.,absorbing the remaining lighter olefnes in concentrated sulphuric acidat 90 C., and hydrolyzing anddistilling to recover alcohols. -A

the remaining v 5. Those steps in the process of making alcohols fromoil gases which comprise selectively absorbing the heavier oleines insulphuric acid at temperatures of '-25o C. to

fines at temperatures of 25 to 20 C., and

then contacting the gas with acid at a higher temperature to absorb theunabsorbed olefines. I v

7. That step in thepr'ocess of manufacturing the higher alcohols fromoil gases which i comprises absorbing the higher olelines of oil gasesin a mixture of concentrated sulpuric acid and sulphuric esters of lowerolelines at a temperature ranging from 20 C. to *25 C.v

8. That step in the processpof manufacturing the higher alcohols'fromioil gases which comprises absorbing the higher olefines of oilgases under pressure of 50 to 200 pounds per square inch in a mixture ofconcentrated sulphuric acid and sulphuric esters of the lower olefines.y

9. That step in the process of manufacturing the higher alcohols fromoil gases Which comprises absorbing the higher olefines in sulphuricacid at temperatures below 5 C.

10. In the process of manufacturing alcohols from oil gases containingolefins, the improvement which -comprises passing said oil gas incontact with successive portions of sulphuric acid maintained atincreasing temperatures in the directionof flow of the gas, andmaintaining each portion of sulphuric acid at a sulphating temperatureadapted to prefins contacted therewith.

11. That step inlthe process of manufacturing alcohol from oil gaseswhich comprises absorbing at temperatures below 20 C. oleine's of oilgases higher in the oleine series thangpropylene in a mixture of acidadapted to absorb oleines and the ethyl and propyl esters of the sameacid.

12. That step in the processof manufacturing alcohol from oil gas whichcomprises compressing oil gas and passing the compressed gas through amixture of sulphuric acid and al l sulphuric acids of the lower olefinesmaintained under sulphating conditions 4and at a pressure equal tothepressure of the gas.

13. A process of making alcohols from oil ases com ris'nfr absorbing thehi her ole- C; which were produced in aseparateA zone,v

maintaining the temperature sufficiently low to prevent substantial.polymerization-.of the 'manana ment in an acid menstruum containingsulphuricacidand ethyl sulphnric acid While-said acid menstruum'ismaintained at a tempera-v ture below 2Go C, absorbing the ethylene ot'the gases in sulphuric acid at a high temperature to form ethylsulphuric acid and supplyingthe ethyl sulphuric acid from the hightemperature absorption to the acid menstruum tor the lovv temperatureabsorption to prevent substantial polymerization of thehigher olenesbeing absorbed.

lli. ln the manufacture of alcohols from a n cracked hydrocarbon gas,the processi comrising treatin a was containin a series ot ole'tines tolremove olelines higher in the series than propylene,v treating the gascontainingpropylene with a solution ot concentra-tedsul- .phuric acidmaintained at a tem? erature' below 20 CD7 hydrolyzing the acidmenstruum and distilling to recover isopropyl alcohol.

17. lin the process of manufacturing alcohols trom cracked hydrocarbongas containing a plurality of olelins together with saturated'hydrocarbons, in which the gas is treated so as to leave a linalgash'aving a comparatively high propylene content, the improvement whichcomprises absorbing thel` propylene content of said gas in a menstruumcontaining sulphuric anid which is maintained at a temperature below 20(l.

i8. ln the process of manufacturing 4isopropyl alcohol from hydrocarbongas containing olehns', in which ol'etins higher than propylene areremoved, the improvement which comprises selectively sulphating thepropylene bycontacting it with an absorbing medium containing'vsulphuric acid .maintained at a ytemperature below that at whichsubstantial amounts of propylene arel polymeri'zed, and hydrolyzing theresultingv propyl sulphate'to produce said isopropyl alcohol., I

19.1 vreactive acid liquor comprising tree" sulphuric acid mixed-Withsubstantial por' tions of sulphurio acid esters o/f the olefine series.consistingprincipally of ethylene to ,heptylena l 20. A reactiveacidliquor comprising a mixture of alkyl SuIphuric'acidsv 'comprisingSubstantial portions of olefines inthe series Vincludingethyleneandother higher olens,

capable on' hydrolysis and distillation el` yielding commercialproportions ol the alcohols 'of the said olefines. '21. ln the method otproducingtpropyl sulphate from gases containing a series of olefins, inwhich olefinshigher than propylene are separated from the remainingconstitu-- ents of said gas, the improvement Which comprises contactingsaid gas containing propylene with concentrated sulphuric acidmaintained at a temperature belovv 20 C., thereby to selectively convertsaid propylene to propyl sulphate.

liti

` 22. A method of forming alkyl sulphates comprising contacting materialcontaining 'mixedolelines with a body of sulphuric acid under conditionsof temperature and length ioit contact adapted to convertsubstantiallyall ot'the oletnes in said material having a molecular Weight as high asbutylene into alkyl sulphates, and thereafter contacting the remainingmaterial containingsnbstantially no olelines of higher molecular Weightthan propylene With a body ot sulphuricacid separate from said firstmentioned body and 1 maintained at a temperature/adapted for theformation of propyl sulphate from the proppylene in said material; britat a temperature notsubstantially Vexceeding 20 C.

23. 'lhe process of making acid alkyl sulphate from gases containingbutylenes and propylene which comprises hrst removing by absorption insnlphuric acid the butylene content of the gases, and then passing thegases in Contact with sulphuric acid ol about 94% concentration and"atta temperature' of under a corresponding acid alkyl sulphate.

ion

30 C. to absorb the propylene and produce 2d. 'llhe process of makingalkyl sulphate i trom olonne-containing gases which comprises absorbingthe butylene and the more easily polymerized products by treating the'gases with sulphuric acid maintained at a temperature adapted torabsorption, then treating the gases with acid at a temperaturev adaptedlor the absorption ofthe propylene and finally treating the remaininggases vvith sulphuric acid and 'at materially higher temperaturesadapted to promote the absorption ot the ethylene whereby alkylsulphat'es corresponding to the several olelines are pro'- duced; 25.-The process ot' making alkyl sulphates from gases containing butylene,`prolfiylene and ethylene which comprises treating "the gases in 'thresuccessive stages or steps With snlphuric acid ot progressivelyincreasin concentrations adapted tor the selective a sorption ofVolefine's, the first two stages vbeing maintained under temperatureconditions adapted for V,the absorption respetively, ot butylene andpropylene and the last st :ageatv ethylene',v to separately H absorb theseveralA oleti'nes substantially in the' order-.ofchemicaly atemperature adapted forth@ absorption of ma ainity, whereby alkylsulphates corresponding to the several oleines are produced.

26. The process of making alkyl sulphates from gases containingbutylene, propylene and ethylene which comprises passing the gasessuccessively through a series of absorbing chambers containing asulphuric acid tially 90 C. whereby 'alkyl sulphates corresponding totheseveral olefines are produced. 27. The process oi' makingl alkylsulphates from oleine-containing gases which comp prises absorbing thebutylene and the more easily polymerized products by treating the gaseswith a weakly reactive sulphuric acid menstruum maintained at atemperature adapted for the absorption `of? butylene, thentreating thegases with a more reactive sulphuric ac id menstruum at slightlyincreased temperature adapted to absorb the propylene and finallytreating thegases with concentrated sulphuric acid and at materiallyhigher temperatures adapted to absorbthe l ethylene whereby alkylsulphates corresponding tothe several olefines are produced. 28.- Theprocess of making acid alkyl sulphates from olefine-containing gaseswhich comprises-subjecting the gases to the absorbing action ofsulphuric acid of concentration and temperature adapted for the fixationof butylenes contained therein, then subjecting the gases to the actionvof sulphuric acid. of

concentration and. temperature adapted for y the fixation of propyle'nc,and finally subjectmainin feu ing the gasesto sulphuric acid ofconcentration and temperature adapted for the fixation of ethyleneWherebythe olefines in the gases are absorbed in the order of theirchemical ainit to produce acid alkyl sulphates correspon ling thereto.

29. The process of producing alkyl sulphates from" olefine-containingmaterials which comprises passing such material through a series ofzones of gradually increasing temperature, introducing concentratedsulphuric acid into thehighest temperature zone' in contact with the`olefin-containing materials therein, passing the acid and absorbedconstituents from said zone through therezones of the series counter tothe fiow o the olefine-bearing' material therethrough, and maintaining asulphating temperature in each zone such as to prevent substantialpolymerization of the material being treated therein.

30. The process of making alkyl sulphates prises passing the gasessuccessively through a series of absorbing chambers in counter currentrelation to the percolation of sulphuric acid of progressivelyincreasing concentrations and at temperatures most suitable to thefixation of the respective olefins to separately absorb the severalolefins and produce said alkyl sulphates corresponding thereto.

31. The process of making alkyl sulphates from olefin-containing gaseswhich comprises passing the gases continuously through a plurality ofseries-connected absorbing chambers, percolating a weakly reactivesulphuric acid menstruum under cool temperature con-l ditions throughthe first portion of the chambers to absorb the more active olefns,andmpercolating sulphuric acid of increased concentration under highertemperature conditions through the last portion of the chambers toabsorb the less active oleins, Vwhereby acid alkyl sulphatescorresponding to the several oleins are produced.

32. The process of making alkyl sulphates from olefin-containing gaseswhich comprises passing the gas through sulphuric acid of concentrationand temperature adapted for the xation of the more reactive olefins,then passing the gases throughpacid of increased concentration butwithoutl substantial increase in temperatureto fix the less reactiveolefins,' and finally passing the gases through l acid of sufficientlyincreased concentration and temperature for the fixation of the leastreactiveolefins, whereby said alkyl sulphates, corresponding to theseveral olefins are produced.4

33. The Aprocess of making alkyl sulphates from olefin-containing gases,which comprises passing the gases through a series of labsorbingchambers for successive treatment therein, contacting the gases bycounter current flow in the chambers of sulphuric acid at progressivelyincreasing concentration and at temperatures most suitable for thefixation of the respective olefins to absorb the several olefinsseparately and produce alkyl sulphates corresponding thereto, whilemaintaining a superatmospheric pressure upon the gases and the-sulphuric'acid throughout the treatment.

In testimony whereof We aflx our signatures. y

SIDNEY BORN. ROBERT MELYNE ISHAM.'

